1. Field of the Invention
The invention relates to a face mask strap, in particular a reversible, quick-adjustable diver's face mask strap which allows for quick and easy readjustment of the mask strap even under water without having to move the mask or release it from sealing against the diver's face.
2. Description of the Prior Art
It has become known in the recent past to replace the older rubber-type mask straps with more convenient fabric-laminated, soft headbands. This new generation of mask straps is gentler to the back of the wearer's head and the tangling of hair is largely avoided. However, the mask strap is not as securely seated on the back of the diver's head as in the case of the old rubber straps.
It has further become known to use quick-adjustable straps such as the one disclosed in U.S. Pat. No. 4,112,521 to Uke.
Soft fabric-laminated mask straps, such as the one disclosed in U.S. Pat. No. 4,910,806 to Baker et al., while offering some advantages over the old rubber straps, have also shown some disadvantageous features. For instance, the soft hook-type fastening material on the inner surface of the strap wears out during extended use, and the connection thereby becomes weaker.
Furthermore, the advantage of avoiding the tangling of hair by using fabrics on the top of the strap to contact the diver's head entails the disadvantage that the strap is not as well positioned on the diver's head as the old rubber-type strap, with its much higher coefficient of friction. Also, the fabric-laminated mask strap is not very suitable for use by a hooded diver, since the strap slides rather easily out of a convenient and secure position on the back of the diver's head.
Yet another problem encountered in using the soft materials for the strap is that while the diver descends into deeper waters the pressure increases. This causes the strap materials such as foam or neoprene to expand and the mask to loose its tight fit on the diver's head. Accordingly, the diver's mask strap must be readjusted quickly when the water pressure increases.